J. F. Dobson | Searcharxiv

arXiv2012

Effects of Spatial Dispersion on the Casimir Force between Graphene Sheets

The Casimir force between graphene sheets is investigated with emphasis on the effect from spatial dispersion using a combination of factors, such as a nonzero chemical potential and an induced energy gap. We distinguish between two regimes for the interaction - T=0 $K$ and $T\neq 0$ $K$. It is found that the quantum mechanical interaction (T=0 $K$) retains its distance dependence regardless of the inclusion of dispersion. The spatial dispersion from the finite temperature Casimir force is found to contribute for the most part from $n=0$ Matsubara term. These effects become important as graphene is tailored to become a poor conductor by inducing a band gap.

cond-mat.mes-hall↗

arXiv2007

High-Level Correlated Approach to the Jellium Surface Energy, Without Uniform-Electron-Gas Input

We resolve the long-standing controversy over the surface energy of simple metals: Density functional methods that require uniform-electron-gas input agree with each other at many levels of sophistication, but not with high-level correlated calculations like Fermi Hypernetted Chain and Diffusion Monte Carlo (DMC) that predict the uniform-gas correlation energy. Here we apply a very high-level correlated approach, the inhomogeneous Singwi-Tosi-Land-Sjölander (ISTLS) method, and find that the density functionals are indeed reliable (because the surface energy is "bulk-like"). ISTLS values are close to recently-revised DMC values. Our work also vindicates the previously-disputed use of uniform-gas-based nonlocal kernels in time-dependent density functional theory.

cond-mat.mtrl-sci↗